We want to see if novel structures can be seen in synapses preserved by high pressure fteezing of wildrype and mutant nematodes. Synapses between identified neurons and muscles in the nematode have been used as a model system to genetically identify new molecules involved in synaptic development and function. These synapses have been well characterized in conventionally fixed samples, however. The subcellular structures that can be seen appear limited compared to the ultrastructure of high pressure frozen samples, e.g., nematode muscle.